﻿//
// (C) Copyright 2009 Irantha Suwandarathna (iranthas@hotmail.com)
// All rights reserved.
//

/* Copyright (c) 2001-2008, The HSQL Development Group
 * All rights reserved.
 *
 * Redistribution and use _in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions _in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer _in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of the HSQL Development Group nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using EffiProz.Core.Errors;
using EffiProz.Core.RowIO;
using EffiProz.Core.Results;
using EffiProz.Core.Indexes;
using EffiProz.Core.Lib;

namespace EffiProz.Core.Navigators
{
    public class RowSetNavigatorLinkedList : RowSetNavigator
    {
        EfzLinkedList list;
        EfzLinkedList.Node root;
        new EfzLinkedList.Node previous;
        EfzLinkedList.Node current;

        public RowSetNavigatorLinkedList()
        {

            list = new EfzLinkedList();
            root = list.getHeadNode();
            current = root;
        }

        /**
         * Returns the current row object. Type of object is implementation defined.
         */
        public override Object[] getCurrent()
        {
            return ((Row)current.data).getData();
        }

        public override Row getCurrentRow()
        {
            return (Row)current.data;
        }

        public override void remove()
        {

            // avoid consecutive removes without next()
            if (previous == null)
            {
                throw new IndexOutOfRangeException();
            }

            if (currentPos < size && currentPos != -1)
            {
                list.removeAfter(previous);

                current = previous;

                size--;
                currentPos--;

                return;
            }

            throw new IndexOutOfRangeException();
        }

        public override bool next()
        {

            bool result = base.next();

            if (result)
            {
                previous = current;
                current = current.next;
            }

            return result;
        }

        public override void reset()
        {
            base.reset();

            current = root;
            previous = null;
        }

        // reading and writing
        public override void write(RowOutputInterface _out,
                          ResultMetaData meta)
        {

            beforeFirst();
            _out.writeLong(id);
            _out.writeInt(size);
            _out.writeInt(0);    // offset
            _out.writeInt(size);

            while (hasNext())
            {
                Object[] data = getNext();

                _out.writeData(meta.getColumnCount(), meta.columnTypes, data, null,
                              null);
            }

            beforeFirst();
        }

        public override void read(RowInputInterface _in,
                         ResultMetaData meta)
        {

            id = _in.readLong();

            int count = _in.readInt();

            _in.readInt();    // offset
            _in.readInt();    // size again

            while (count-- > 0)
            {
                add(_in.readData(meta.columnTypes));
            }
        }

        public override void clear()
        {

            reset();
            list.clear();

            size = 0;
        }

        /**
         *  Method declaration
         *
         * @param  d
         */
        public override void add(Object d)
        {

            list.add(d);
            size++;
        }
    }
}
